TECHNICAL FIELD
[0001] The invention relates to a wing for an aircraft, an aircraft having such a wing as
well as the use of a sealing device.
BACKGROUND OF THE INVENTION
[0002] Currently used and known concepts for providing high lift devices on a wing of an
aircraft are usually based on movable aerodynamically shaped profiles. These profiles
may be realized as reinforced panels or other wing sections, which are selectively
moved to different positions through the use of a drive system. A drive system usually
consists of actuators and kinematic elements, like rods, linkages and tracks with
rails and carriages. High lift systems often include movable elements at a leading
edge as well as at a trailing edge. Throughout many decades, several different concepts
have evolved, which utilize different flaps and leading edge slats. Through moving
the respective high lift devices, a resulting surface area, a resulting camber as
well as the existence and size of gaps is adjustable, thereby influencing the lift
coefficient of the wing.
[0003] For improving the overall aerodynamic characteristics of the wing, high lift components
are usually designed to have a certain shape that allows to influence the air flow
as harmonic as possible. Additional installations are sometimes used to provide a
further improvement of the aerodynamic characteristics regarding drag and noise. However,
these aerodynamic devices require a certain installation space and a related manufacturing
effort.
[0004] For example,
US 2007 0241 236 A1 shows an aircraft having a wing defining an aerofoil surface, the wing comprising
a drooped leading edge flap being moveable between a stowed position and a deployed
position, wherein the wing is so arranged that during flight when the high-lift device
is in the deployed position, air may flow through an opening in the wing and over
the aerofoil surface. During flight, air preferably flows into the boundary layer
on the upper surface of the wing. This energises the boundary layer, aft of the trailing
edge of the drooped leading edge flap increasing its stability allowing the maximum
achievable lift coefficient to be increased and hence reducing aircraft take-off and
approach speeds.
[0005] Still further,
US 6 789 769 B2 shows a slat selectively extendable from a main wing body, with a concave rear surface
of the slat facing a convex forward nose surface of the wing body, with a slat gap
therebetween. Flexible bristles are movably arranged relative to the lower rear edge
of the slat, to flexibly protrude up into the slat air gap, which bristles are flexibly
self-positioning and self-contouring due to the aerodynamic forces acting thereon,
to improve the air flow conditions through the slat gap, separate the slat gap airflow
from an entrapped eddy vortex on the concave rear surface of the slat, and thereby
reduce the aerodynamic noise generated along the slat gap.
SUMMARY OF THE INVENTION
[0006] It is therefore considered an object of the invention to provide a high lift system
for a wing of an aircraft, a high lift device movably arranged at a wing of an aircraft
and/or a wing of an aircraft having such a high lift system or device, which lead
to a reduction in manufacturing effort, a reduction of a required installation space,
a reduction of complexity as well as maintaining or improving the aerodynamic characteristics.
[0007] The object is met by a wing for an aircraft having the features of independent claim
1. Advantageous embodiments and further improvements may be gathered from the sub-claims
and the following description.
[0008] It is proposed a wing for an aircraft, comprising a main wing structure fixedly attachable
to a body of an aircraft, at least one high lift body movably supported at the main
wing structure, a drive unit coupled with the main wing structure and the at least
one high lift body and adapted to move the at least one high lift body relatively
to the main wing structure in a substantial chordwise direction between a retracted
position and at least one extended position and a sealing device coupled with the
at least one high lift body and the main wing structure. The at least one high lift
body comprises at least one outer edge facing to the main wing structure, which edge
creates a gap to the main wing structure at least in an extended position. The sealing
device comprises a flexible sealing body, which seals the intermediate space between
the at least one high lift body and the main wing structure at least in extended positions
of the at least one high lift body.
[0009] The main wing structure is a main structural, load carrying component of a wing.
It may be designed in a box-like manner having at least two spars running in a spanwise
direction, which are coupled with a plurality of parallelly arranged ribs.
[0010] A skin surrounds this arrangement of ribs and spars. A part of this construction
may be sealed in order to serve as a fuel tank. The material and the design of the
main wing structure depends on the general design philosophy of the respective aircraft
and may utilise metallic material as well as fibre-reinforced materials.
[0011] The at least one high lift body may be a single component or a plurality of components,
which are attached to a plurality of different positions or regions of the main wing
structure. For example, the at least one high lift body may be a leading edge high
lift body arranged in a leading edge region of the wing. Also, the at least one high
lift body may be a trailing edge flap arranged at a trailing edge region of the wing.
A combination of these different components may also be possible. Additionally, also
flaps and spoilers may be present, which are arranged at an upper or a lower surface
of the main wing structure and which are designed according to the core aspects of
the invention.
[0012] In general, the design of the at least one high lift body is not particularly relevant
for the core of the invention. However, in the following description, some exemplary
embodiments are given, which serve as examples and are not intended to limit the invention
to one of these. However, due to the use of the sealing device further explained below,
the at least one high lift body may comprise a much more simple and smaller construction
compared to commonly used high lift bodies.
[0013] The sealing body may be a surface-like, flexible element, which allows to be pulled
over a gap between the at least one high lift body and the main wing structure and
which allows to remain there when held on at least two sides. It may be particularly
feasible to use a foil made from a plastics material. Additionally, reinforcement
fibers or wires may be integrated therein. For example, a polyaramide foil or a foil
reinforced with polyaramide fibers is advantageous. Also, a polyaramide fabric together
with a polychloroprene coating is feasible. Still further, a polyester fabric is a
feasible material.
[0014] The drive unit for moving the at least one high lift body relative to the main wing
structure may be arbitrarily chosen, as long as it is capable of conducting the task
of moving the at least one high lift body relative to the main wing structure. For
example, the drive unit may comprise a fluid actuator, such as a hydraulic actuator.
As an alternative, the drive unit may comprise an electric actuator, such as an electric
motor mechanically coupled with a gear. The required extension and retraction velocities
may depend on the desired installation position and size of the respective high lift
body. Commonly, they are not necessarily high for the task of high lift generation.
It may therefore be feasible to use an actuator with a substantially arbitrary motion
speed.
[0015] The drive unit may be self-locking, such that an acquired position of the drive unit
remains when the drive unit is switched off. The self-locking feature may be an intrinsic
feature of the drive unit, such as in a spindle gear with a certain thread pitch.
However, the self-locking feature may be realised in form of a separate device, such
as with a separately operable locking unit or a brake.
[0016] Still further, the drive unit may include a guide device that is able to guide the
at least one high lift body along a desired motion path. This may be the case with
a spindle gear, where at least a part of the high lift device to be moved may be held
on the spindle or a nut engaging the spindle.
[0017] However, the drive unit may also be a separate device, which moves the high lift
device along a separate guide device.
[0018] In this regard it is noted that the retracted position as mentioned above is to be
considered a position, in which the at least one high lift body substantially closes
the contour of the wing in order to form a clean wing. A retracted position is a position,
in which the at least one high lift device is moved away from the clean wing or retracted
position.
[0019] A core aspect of the wing according to the invention lies in using the sealing device,
which comprises a flexible sealing body for sealing an intermediate space between
the at least one high lift body and the main wing structure in extended positions
of the at least one high lift body. The flexible sealing body in these positions extends
between the at least one high lift body and the main wing structure, such that this
intermediate space is basically closed. In other words, the intermediate space is
covered by a flexible sealing element, that avoids an airflow transverse to the surface
of the sealing body. For this purpose, the sealing body should be air-impermeable.
[0020] This leads to a simplified design of the at least one high lift body, since the actively
movable part of the high lift body may be dimensioned smaller, while the aerodynamic
characteristics of the combination of high lift body and sealing device are improved
at the same time.
[0021] In an advantageous embodiment, the at least one high lift body comprises a nose body
providing a movable leading edge for the wing. The nose body may be designed as simple
as a bull nose, i.e. a rounded edge. Particularly with a nose body, an intermediate
space between an upper trailing edge of the nose body and the associated leading edge
of the wing structure, which faces to the upper trailing edge of the nose body, may
be covered by a sealing body. Consequently, at least an upper section of the wing
will comprise a closed flow surface, while the lower surface may optionally be closed
as well.
[0022] In a further advantageous embodiment, the at least one high lift body comprises a
flap providing a movable trailing edge of the wing. Here, the at least one high lift
body may provide a translational motion relative to the wing structure, which leads
to a gap between the wing structure and the flap. A part of this gap may be covered
by a spoiler, an air brake or another similar component, while at least a part of
the intermediate space between the wing structure and the flap may be covered by said
sealing body. Of course it is possible to provide the trailing edge flap in addition
to the leading edge nose body and vice versa.
[0023] In a further advantageous embodiment, the sealing device comprises a retraction device
attachable to one of the at least one high lift body and the wing structure, wherein
the retraction device is adapted for selectively releasing and storing the flexible
sealing body in the one of the high lift body and the wing structure. This allows
to selectively expand the area to be sealed by the sealing body for preventing the
fluttering of an excess length of the sealing body. The retraction device may be realised
based on a variety of different operation principles. For example, the sealing body
may simply be retractable through pulling it into the main wing structure or a hollow
space of the at least one high lift body. While the latter may comprise a rather small
free space, it may be feasible to include the retraction device in the main wing structure.
The sealing body may be stored through rolling, winding, folding or other processes.
[0024] In a preferred embodiment, the retraction device is a winding device, which comprises
a rotatably supported winding reel for winding up or unwinding the sealing body. Of
course, the sealing body must be designed for this purpose, i.e. by being sufficiently
flexible to allow a rollability or windability, respectively. The winding reel may
be driven by a motor or through a passive device, such as a spring.
[0025] The sealing body may comprise a plurality of longitudinal stiffening elements attached
to an inner side of the sealing body and substantially extending along a spanwise
direction. These stiffening elements may be realised as stringers comparable to common
stringers attached to an inner side of a wing skin. However, due to the considered
retraction the stiffening elements may comprise a more flat profile. The stiffening
elements provide a stiffening function for the sealing body, such that at least in
a lateral direction, i.e. parallel to the leading edge and/or the trailing edge, a
bending of the sealing body is substantially adjusted. In order to allow a rollability/windability
or foldability, the stringers may preferably comprise a flat profile, which should
extend as little as possible in a direction perpendicular to the sealing body.
[0026] In a preferred embodiment, the retraction device is adapted for providing a tensioning
force onto the sealing body in at least one extended position of the at least one
high lift body. By providing a certain tensioning force onto the sealing body, the
shape of the sealing body can be influenced. For example, the sealing body may be
pulled tight, which will support its shape through pretension. Further, a potential
fluttering tendency of the sealing body is substantially avoided.
[0027] However, in case a certain camber of the wing in the region of the at least one high
lift body is required, pulling the sealing body straight should be avoided. As an
alternative to merely pulling the sealing body straight, the extension of the sealing
body between the at least one high lift body and the main wing structure may exceed
the distance between the at least one high lift body and the main wing structure.
Hence, an overlength of the sealing body is present, which is flown over by air. As
this air flow leads to a certain suction force, the sealing body will assume a certain
profile shape. By controlling the excess length of the sealing body, the profile shape
is controllable to a certain extent.
[0028] As a further measure, at least a profile body may be provided, which profile body
is movably supported on the main wing structure, wherein the at least one profile
body is arranged on a suction side of the sealing body, such that it is pressed against
the at least one profile body when pulled out from the main wing structure. For example,
a single or a plurality of profile bodies may be placed above the sealing body, such
that the sealing body is able to be pressed against the sealing body. The at least
one profile body then determines the overall shape of the sealing body and the wing,
respectively.
[0029] In order to support the shape of the sealing body, a plurality of inflatable tubes
are provided, which are substantially arranged in a chordwise direction and at a distance
to each other. Preferably, the tubes are self-inflating. For allowing air to enter
the tubes, the tubes may comprise a valve at a front region facing to the leading
edge high lift body. Particularly when a winding device is used to wind up the sealing
device, the tubes will be emptied and flattened.
[0030] Furthermore, the winding device may comprise a spring mechanism, which is adapted
for pulling the sealing body, such that it provides a tension onto the sealing body.
The sealing body is then released by simply moving the at least one high lift body
and stored by simply retracting the high lift body.
[0031] In a particularly preferred embodiment, the stringers may be inflatable, such that
they comprise a flattened stowage state and an inflated use state. The inflation may
be conducted actively, i.e. through an inflation device, which may be in a fluid communication
with the inflatable stringers. As an alternative, the inflatable stringers may be
coupled with an air inlet that is in fluid communication to an exterior of the sealing
body, such that when an airflow is present, the stringers are passively inflated.
For example, an air inlet facing into the flight direction may receive a flow of air,
which is lead to the inflatable stringers. In case the sealing body is stored through
winding it up, the inflatable stringers are compressed, such that the air is pressed
out and they assume their flattened stowage state.
[0032] The drive unit is adapted for moving the at least one high lift body in a first direction.
In a further advantageous embodiment, the wing comprises an auxiliary drive unit,
which is adapted for moving the at least one high lift body in a second direction,
which differs from the first direction, independently from the drive unit. In this
case, the at least one high lift body conducts a motion, in which the individual motions
induced by the drive unit and the auxiliary drive unit are superposed. For example,
the auxiliary drive unit may be arranged directly in the at least one high lift body
and be adapted for adjusting an angle of the at least one high lift body in relation
to the air flow. If the high lift body is a nose body, the second direction may be
a downward direction, which allows the nose body to be drooped.
[0033] In another embodiment, the sealing body may comprise a plurality of holes, which
are arranged in at least a rearward part of the sealing body, i.e. in a region which
is extended only close to or at a fully extended position of the high lift body. This
allows to provide similar technical effects as a common gap between the main wing
structure and the high lift body, i.e. to let flow with a high flow energy pass from
one side of the wing to the other, preferably in order to delay stall.
BRIEF DESCRIPTION OF THE FIGURES
[0034] Other characteristics, advantages and potential applications of the present invention
result from the following description of the exemplary embodiments illustrated in
the figures. In this respect, all described and/or graphically illustrated characteristics
also form the object of the invention individually and in arbitrary combination regardless
of their composition in the individual claims or their references to other claims.
Furthermore, identical or similar objects are identified by the same reference symbols
in the figures.
Fig. 1 shows a first exemplary embodiment in a side view.
Fig. 2 shows a detail of the first exemplary embodiment in a side view.
Fig. 3 shows a further embodiment.
Fig. 4a and 4b show a further exemplary embodiment with a droop kinematics.
Fig. 5 shows an exemplary embodiment with spanwise stiffeners and chordwise tubes
in a spatial view.
Fig. 6a to 6c show different exemplary embodiments with varying lengths of sealing
bodies.
DETAILED DESCRIPTION OF THE DRAWINGS
[0035] Fig. 1 shows a wing 2 in a side view. The left side of the drawing plane illustrates
a leading edge region 4, while on the right side of the drawing plane, a trailing
edge region 6 is shown. For the sake of simplified illustration, the interior of the
wing 2 is substantially empty and the outer contour of the wing 2 is simplified.
[0036] In this exemplary embodiment, a nose body 8, which is arranged in the leading edge
region 4, is separated from a main wing structure 10, which is the main structural
part of the wing 2 attachable to a fuselage of an aircraft. As stated in the above
description of the invention, the main wing structure 10 comprises a certain interior
design, which provides a mechanical stability.
[0037] The nose body 8 is coupled with a drive unit 12, which exemplarily comprises a spindle
14, at least one nut 16 and a motor 18. The spindle 14 extends from the motor 18 to
the nose body 8 and is supported by exemplarily two support beams 20 and 22, which
are mechanically fixed to the main wing structure 10.
[0038] By rotating the motor 18, the spindle 14 rotates and induces a motion along the nut
16 along its extension axis. The orientation of the spindle 14 and, resultantly, the
direction of linear motion, may be chosen to meet the needs for moving the nose body
8. To avoid a rotation of the nose body 8, a certain support 24 may be arranged on
an inner side of the nose body 8.
[0039] Nose body 8 comprises an upper trailing edge 26 as well as a lower trailing edge
28, which together enclose a C-shaped profile. Furthermore, the main wing structure
10 comprises an upper leading edge 30 as well as a lower leading edge 32, which both
face to the nose body 8. A sealing body 34 extends between the upper trailing edge
26 and the upper leading edge 30, wherein in this illustration the nose body 8 is
in an extended position. Hence, a gap 36 between the upper trailing edge 26 and the
upper leading edge 30 is closed by the sealing body 34.
[0040] As more apparent in Fig. 2, the sealing body 34 is wound up in a winding reel 38,
which is able to rotate around a winding axis 40 to selectively release or store the
sealing body 34. Hence, by extending the nose body 8, the sealing body 34 may be released
through covering the gap 36 with increased dimensions.
[0041] It is advantageous if the winding device 40 comprises a spring mechanism (not shown),
which is constantly urging the sealing body 34 onto the winding reel 38. This is indicated
by an arrow in clockwise direction of the winding reel 38.
[0042] As even more apparent in Fig. 3, the sealing body 34 comprises a plurality of flat
stringers 42, which are arranged on an inner side 44 of the sealing body 34. These
allow to improve the stability of the sealing body 34 in a direction perpendicular
to the drawing plane. The stringers 42 may thus extend parallel to the winding axis
40.
[0043] The winding reel 38 may be coupled with a retraction device or a winding device 39,
which is able to rotate the winding reel 38 in order to store or release the sealing
body 34.
[0044] In Figs. 4a and 4b another exemplary embodiment is shown, which is based on the exemplary
embodiment shown in Figs. 1 and 2. Here, the spindle 14 is guided by a support beam
46, which is swivably mounted in the interior of the wing. The support beam 46 may
comprise a swivably mounted bearing, which is indicated by the dashed lines in the
support beam 46, through which bearing the spindle 14 extends. The nose body 8 is
again coupled with a drive unit 12, is driven by a motor 18. The spindle 14 extends
from the motor 18 to the nose body 8 through the support beams 22 and 46. Once the
spindle 14 is forwarded, the support beam 46 swivels in a way that the spindle 14
and the nose body 8 are lowered. Hence, the wing has a droop nose. In this example
the sealing body 34 linearly extends between the upper leading edge 30 to the upper
trailing edge 26 of the nose body 8. While Fig. 4a shows a retracted position, Fig.
4b shows an extended position. The sealing body 34 in this case has an angle of approximately
20-25° to the sealing body 34 in Fig. 2. The nose body 8 is moved downwardly.
[0045] Fig. 5 shows a part of a wing in a spatial direction. Here, a plurality of spanwise
stiffening elements in the form of stringers 42 are shown, which are sewn into the
sealing body 34. Further, chordwise inflatable tubes 48 are arranged at a distance
to each other and substantially extends along the whole chordwise extension of the
sealing body 34. At a front region 50 they may each comprise a valve (not shown) that
allows to inflate the tubes 48 and to maintain a certain fluid pressure. They are
openable to release the pressure again, thereby allowing to retract the sealing body
34 again.
[0046] As another feature chordwise profile bodies 52 are used, which are extendable separately
or together with the sealing body 34. These allow to let the sealing body 34 rest
on an underside of the profile bodies when air flows over the upper surface of the
sealing body 34 and creates a suction force on the sealing body 34.
[0047] At an end of the sealing body 34 in close proximity to the main wing structure 10,
several flow openings 54 are present, which allow an energetic flow of air to pass
from an underside 56 to an upper side 58 of the wing, e.g. in order to delay stall.
The openings 54 comprise a reinforced foil or rim 60.
[0048] Finally, Fig. 6a to 6c show various options for realising the sealing body 34. In
Fig. 6a the sealing body 34 comprises an excess length, which allows to provide a
certain bulging once a suction force occurs on the upper side through the surrounding
air flow. Hence, a certain shape of the wing including the nose body 8 and the sealing
body 34 may be reached.
[0049] Fig. 6b shows a sealing body 34, which is pulled straight after extending the nose
body 8. The resulting overall shape is somewhat angular.
[0050] Fig. 6c resembles the exemplary embodiment from Fig. 5, where profile bodies 52 are
used for limiting the bulging of the sealing body 34.
[0051] In addition, it should be pointed out that "comprising" does not exclude other elements
or steps, and "a" or "an" does not exclude a plural number. Furthermore, it should
be pointed out that characteristics or steps which have been described with reference
to one of the above exemplary embodiments may also be used in combination with other
characteristics or steps of other exemplary embodiments described above. Reference
characters in the claims are not to be interpreted as limitations.
1. Wing (2, 43, 47) for an aircraft comprising
a main wing structure (10) fixedly attachable to a body of an aircraft,
at least one high lift body (8) movably supported at the main wing structure (10),
a drive unit (12) coupled with the main wing structure (10) and the at least one high
lift body and adapted to move the at least one high lift body (8) relative to the
main wing structure (10) in a substantial chordwise direction between a retracted
position and at least one extended position, and
a sealing device coupled with the at least one high lift body (8) and the main wing
structure (10),
wherein the at least one high lift body (8) comprises at least one outer edge (26,
28) facing the main wing structure (10), which at least one outer edge (26, 28) creates
a gap (36) to the main wing structure (10) at least in an extended position,
wherein the sealing device comprises a flexible sealing body (34), which seals the
gap (36) between the at least one high lift body (8) and the main wing structure (10)
in extended positions of the at least one high lift body (8).
2. Wing (2, 43, 47) according to claim 1,
wherein the at least one high lift body (8) comprises a nose body providing a movable
leading edge of the wing (2, 43, 47).
3. Wing (2, 43, 47) according to claim 1 or 2,
wherein the at least one high lift body (8) comprises a flap providing a movable trailing
edge of the wing (2, 43, 47).
4. Wing (2, 43, 47) according to any of the previous claims,
wherein the sealing device comprises a retraction device (39) attachable to one of
the high lift body (8) and the wing structure (10), wherein the retraction device
(39) is adapted for selectively releasing and storing the sealing body (34) in the
one of the high lift body (8) and the wing structure (10).
5. Wing (2, 43, 47) according to claim 4,
wherein the retraction device (39) is a winding device comprising a rotatably supported
winding reel (38) for winding up or unwinding the sealing body (34).
6. Wing (2, 43, 47) according to any of the preceding claims,
wherein the sealing body (34) comprises a plurality of longitudinal stiffening elements
(42) attached to an inner side of the sealing body (34) and substantially extending
along a spanwise direction.
7. Wing (2, 43, 47) according to claim 6,
wherein the winding device (39) comprises a spring mechanism, which is adapted for
pulling the sealing body (34) straight, such that it provides a tension onto the sealing
body (34).
8. Wing (2, 43, 47) according to any of the preceding claims,
wherein the longitudinal stiffening elements (42) are inflatable, such that they comprise
a flattened stowage state and an inflated use state.
9. Wing (2, 43, 47) according to any of the preceding claims,
further comprising at least one profile body (52), which is movably supported on the
main wing structure (10),
wherein the at least one profile body (52) is arranged on a suction side of the sealing
body (34), such that it is pressed against the at least one profile body (34) when
pulled out from the main wing structure (10).
10. Wing (2, 43, 47) according to any of the preceding claims,
further comprising a plurality of inflatable tubes (48), which are substantially arranged
in a chordwise direction and at a distance to each other
11. Wing (2, 43, 47) according to any of the preceding claims,
wherein the wing (2, 43, 47) comprises an auxiliary drive unit (24), which is adapted
for moving the at least one high lift body (8) in a second direction independently,
which second direction differs from a first direction caused by the drive unit (12).
12. Aircraft having a fuselage and at least one wing (2, 43, 47) according to claims 1
to 11 attached to the fuselage.